Only Label Contours Exceeding a Minumum Length

[camden.n.dean]

I have a lidar survey of a jetty. This leads to lots of really tightly spaced contours. I'm looking for a way to only label contours that exceed a minimum length requirement. 

In the above image, the contour with the red box is ≈15' long, and i do not want it labeled. Whereas the contour in the green box is 100'+ long and I do want it labeled. 

Anyone know a solution for this? 

-Camden

[ChrisRS]

What are we seeing in your image?

Is that a Civil 3D surface stylized with contours and contour labels?
Is it polylines with text objects?

I would expect Civil 3D labels to be aligned with the contours rather than aligned horizontally.

Civil 3D Surfaces, stylized to display contours, consist of one surface object.

• There are no individual contour objects. There is nothing to evaluate programmatically.
• I would use Contour -Multiple labels and place the sample line carefully, avoiding the short lines. 

If these are in fact polylines and text components, you could write a list routine to step through each polyline and compute the bounding box dimension.
These dimensions can be used to classify long or short.

• A text object could be placed at the midpoint. This would not be trivial to write.
• Alternatively, long and short lines could be moved to "long" and "short" layers.
  Use Layiso and label the long lines by whatever method you like.
  Dynamo may be useful for this.
• Note your long contours may be segmented and require joining.

Good luck. 

[camden.n.dean]

@ChrisRS 

What you are looking at is a volume surface with elevation analysis and minor contours at 0.5' intervals, and major contours at 2.5' intervals. The labels are aligned to the view instead of the contour objects, but they are indeed contour labels (placed via Contour - Single).

From your post I take it that there is no systematic way to do this within the program. If I want to do this systematically, I would need to first export the contours then write and run the lisp that you described. This would also mean that whenever my survey is updated that I would need to remember to rerun this process of extracting contours and running the lisp. 

As you say, I could just place my labels carefully. This will technically work, but will be slow and a bit painful. It also is likely to require a fair bit of manual rework when my survey data is updated. 

TLDR; there is no automated way to do this, but there are a few ways to accomplish it semi-manually. 

Thanks for your time, Chris. It's helpful to hear from someone else with experience that this is indeed not something that Civil3D can do currently.